From the outside, there isn't a lot to distinguish the HIS Radeon HD 6870 Turbo from a reference model of the HD 6870.

There's a new heatsink slapped over the top of the enormous double slot card which, like all HD 6870s, requires two extra power connectors and will take up any spare room you have in your case.

Other than that, though, it has the same five outputs which – excitingly, for fans of the third dimension – includes support for technologies such as Blu-ray 3D via HDMI 1.4.

The Turbo suffix signifies, of course, that this is a factory-overclocked version of the HD 6870.

For the moderate price increase of around £10 over, say, the stock-clocked Sapphire HD 6870, there's a correspondingly moderate acceleration of the core clock speed from 900MHz to 920MHz with another 50MHz tacked onto the memory speed for luck.

With a card as big and complex as the HD 6870 is, can such a relatively small change make much of a difference?